A Within-Animal Comparison of Skilled Forelimb Assessments in Rats

Abstract

A variety of skilled reaching tasks have been developed to evaluate forelimb function in rodent models. The single pellet skilled reaching task and pasta matrix task have provided valuable insight into recovery of forelimb function in models of neurological injury and disease. Recently, several automated measures have been developed to reduce the cost and time burden of forelimb assessment in rodents. Here, we provide a within-subject comparison of three common forelimb assessments to allow direct evaluation of sensitivity and efficiency across tasks. Rats were trained to perform the single pellet skilled reaching task, the pasta matrix task, and the isometric pull task. Once proficient on all three tasks, rats received an ischemic lesion of motor cortex and striatum to impair use of the trained limb. On the second week post-lesion, all three tasks measured a significant deficit in forelimb function. Performance was well-correlated across tasks. By the sixth week post-lesion, only the isometric pull task measured a significant deficit in forelimb function, suggesting that this task is more sensitive to chronic impairments. The number of training days required to reach asymptotic performance was longer for the isometric pull task, but the total experimenter time required to collect and analyze data was substantially lower. These findings suggest that the isometric pull task represents an efficient, sensitive measure of forelimb function to facilitate preclinical evaluation in models of neurological injury and disease.

The supination assessment task: An automated method for quantifying forelimb rotational function in rats

“…Recently, several automated methods of evaluating motor function in the rat have been developed (Hays et al 2013a, 2013b; Poddar et al 2013; Jarrahi et al 2015; Kawai et al 2015; Sloan et al 2015; Wong et al 2015; Becker et al 2016). Automation of motor assessments obviates many limitations of traditional assessments such as single pellet retrieval, permitting high-throughput testing and potentially decreasing the cost and time of running experiments.…”

“…Unilateral motor cortex ischemic lesions were administered similar to previously described (Hays et al 2013a, 2013b, 2014; Khodaparast et al 2013, 2014, 2015; Sloan et al 2015). Rats were anesthetized with ketamine hydrochloride (80mg/kg, i.p.)…”

Awake behaving electrophysiological correlates of forelimb hyperreflexia, weakness and disrupted muscular synchronization following cervical spinal cord injury in the rat

“…The isometric pull task has been shown to be a sensitive measure of impaired volitional forelimb strength in previous studies on ischemic stroke and traumatic brain injury [37,40,76]. It is a quantitative and automated task that allows for many trials of forelimb behavior and therefore statistical power, without necessitating manual video analysis or live scoring of behavior.…”

The Pedunculopontine Tegmental Nucleus as a Motor and Cognitive Interface between the Cerebellum and Basal Ganglia

“…Various human brainstem nuclei, specifically the PPTg, cuneiform, and subcuneiform nuclei, exhibited increased activity when participants were asked to imagine that they were walking, and these have been found to correspond to the MLR (Tattersall et al, 2014). The PPTg is regarded as being involved in locomotion, while the anatomical contribution of the PPTg to the MLR is still controversial, but it is regarded as being involved in locomotion, which is one of the main functions of MLR (Ryczko and Dubuc, 2013; Sloan et al, 2015). As low-threshold electrical stimulation of the PPTg induces locomotion (Garcia-Rill et al, 1987), it has been accepted that the PPTg acts as a relay from the basal ganglia to the spinal cord (Takakusaki et al, 2004a).…”